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  • Researchers analysed data from a cohort of people in Canada living with HIV and co-infected with hepatitis C
  • Direct-acting antivirals led to an increase in hepatitis C treatment initiation in this cohort after 2014
  • However, 46% of participants still had a hepatitis C infection at their last study visit

Hepatitis C virus (HCV) infects the liver. If the immune system is unable to clear the virus, chronic HCV infection occurs. Over time, this viral infection can degrade the health of the liver. This leads to serious complications and increases the risk of liver cancer and death.

Due to shared routes of infection, some people with HCV are also co-infected with HIV. As HIV weakens the immune system, co-infection accelerates the pace of HCV-related liver injury and death.

Leading Canadian scientists estimate that about 85% of new HCV infections in Canada occur among people who inject drugs (PWID). Additionally, research indicates that about 10% of PWID in Canada have both HIV and HCV. However, many people with HCV (some of whom also have HIV) may not be aware that they have HCV and that they need care and treatment.

The evolution of HCV treatment

Twenty years ago, the leading treatment for HCV consisted of regular injections of interferon with or without the broad-spectrum antiviral drug ribavirin, taken in pill form. These medicines could cause generally unpleasant and, in some cases, dangerous side effects. As a result, not all people with HCV initiated treatment back then.

However, beginning in 2014, powerful anti-HCV drugs that could be taken orally were developed. These drugs, called direct-acting antivirals (DAAs), were designed to attack HCV. Combinations of DAAs have been developed that can be taken once daily. In some cases, treatment for as short as eight consecutive weeks can cure HCV. Commonly used DAAs in Canada and other high-income countries today include the following:

  • Epclusa – sofosbuvir + velpatasvir
  • Harvoni – sofosbuvir + ledipasvir
  • Maviret – glecaprevir + pibrentasvir

These drugs are now subsidized by provincial and territorial drug formularies.

In Canada

A team of researchers with the Canadian Coinfection Cohort assessed data they collected to understand participants’ engagement with harm reduction, drug use and HCV treatment.

Information from participants living in the following provinces was analysed:

  • British Columbia
  • Saskatchewan
  • Ontario
  • Quebec

The data were collected from 2003 to 2019 from 1,077 people.

The researchers found the following trends:

  • The effectiveness of treatment increased over time (as treatments became simpler, safer and more effective), and the proportions of people who were cured rose, particularly in the latter part of the study.
  • Although patterns of drug use varied from one province to another, there was an overall decrease in injecting cocaine and an increase in injecting opioids over time.
  • Gaps in the use of harm reduction services persisted and rates of opioid substitution (use of buprenorphine or methadone) remained low—between 8% and 26%.

Although improvements in HCV rates of cure occurred during the study, gaps in the use of harm reduction services left many PWID at risk for drug-related harms. According to the researchers, their findings reveal that much work remains to be done to “improve the overall health of [PWID].”

Study details

The Canadian Coinfection Cohort is an ongoing study of people with both HCV and HIV. It has recruited more than 2,000 participants from six provinces.

Participants are scheduled for study visits every six months. At these visits, information on a number of topics—including drug use and engagement with harm reduction services—is obtained, as are blood samples for analysis. Additional information was gathered from medical charts of participants.

On average, participants were mostly male—between 57% and 80%, depending on the province of residence.


In general, the proportion of people who initiated HCV treatment remained low until about 2014. Once combinations of powerful DAAs became available, rates of HCV treatment initiation increased. However, despite this change, the researchers noted that 46% of participants were still infected with HCV at their last study visit.

The practice of sharing needles or syringes decreased over time. In general, the researchers found that sharing needles/syringes was more common in Ontario and least common in British Columbia.

Trends in drug use

In the latter years of the study (2014 to 2019), cocaine was the most commonly injected drug in Ontario and Quebec. In Saskatchewan and B.C., opioids were injected more frequently than cocaine.

The researchers found methamphetamine use increased between 2014 and 2019, as did the use of a class of medicines called benzodiazepines (drugs such as Valium belong to this class of medicines).

New needles and syringes

In the earlier part of the study (2003 to 2013), use of harm reduction services—specifically obtaining new needles/syringes—remained stable. However, from 2014 on, engagement with harm reduction services decreased. The researchers are not certain why this occurred. Due to this unexpected finding, further research is needed to confirm and understand why participants’ engagement with harm reduction services decreased. The researchers noted that such a decrease did not occur among Canadian PWID outside the study cohort during the same period.

Opioid substitution therapy

Overall, the researchers found that the use of opioid substitution therapy was “relatively low and stable over time.” More people from B.C. were likely to use buprenorphine or methadone compared to people from other provinces.

Bear in mind

An important overall trend in the study was the increased use of DAAs and cure of HCV over time. However, this good news was tempered by other findings. The researchers stated that “sharing of needles or syringes continues to be reported [by participants], and substantial gaps remain in engagement with harm reduction programs.”

Thus, much work and investment in the care needs of people who use drugs lies ahead as opportunities for harm reduction and HCV treatment need to be intensified. Furthermore, increasing the availability of harm reduction services and HCV treatment can help accelerate efforts to eliminate HCV as a public health issue by 2030.

For the future

The researchers advanced the following steps to improve the health of PWID:

  • increased government funding for HCV health services and research
  • the formation of multidisciplinary teams at clinics where the needs of PWID beyond HCV care can be met
  • involving peers with relatable and lived experience to help PWID access health services
  • HCV awareness campaigns and patient education resources at community organizations

To improve access to harm reduction services, the researchers recommended the following steps:

  • sustained government funding of harm reduction programs
  • integration of services for HIV and HCV care and harm reduction
  • involvement of peers to help PWID navigate these services

To reduce overdoses and deaths from the poisoned supply of street drugs, the researchers made the following recommendations:

  • continued distribution of naloxone
  • drug decriminalization
  • provision of a safe supply of drugs
  • facilitation of education for healthcare providers about pain management and treatment of drug dependency

—Sean R. Hosein


Supervised opioid use combined with housing and other services found to improve health outcomes for people who use drugsCATIE News

Study explores hepatitis C virus reinfection in Victoria, British ColumbiaCATIE News

Hepatitis C - CATIE

Understanding Cirrhosis of the Liver: First steps for the newly diagnosed – CATIE, Canadian Association of Hepatology Nurses (CAHN)

What Works: What you need to know if you have HIV and use drugs – CATIE

Best Practice Recommendations for Canadian Harm Reduction Programs – Working Group on Best Practice for Harm Reduction Programs in Canada

Connecting with hepatitis C care during COVID-19International Network on Health and Hepatitis in Substance Users (INHSU), the Canadian Network on Hepatitis C (CanHepC) and CATIE


Lanièce Delaunay C, Maheu-Giroux M, Marathe G, et al. Gaps in hepatitis C virus prevention and care for HIV–hepatitis C virus co-infected people who inject drugs in Canada. International Journal of Drug Policy. 2022; in press.